1. Field of the Invention
The present invention relates to a connection system useful in eyewear frames, and more particularly, relates to a connection system for connecting two components, such as a plastic component and a metal component in the temple of an eyewear frame.
2. Description of the Art
Eyewear, such as sunglasses or spectacles, typically comprise a front frame, temple members which extend out and over the ear of the wearer, and hinge systems for attaching the temples to the front frames. Conventionally, eyewear frames have been made from plastics, such as various acetates, or from metals, such as nickel or copper alloys plated with a precious metal. Plastic frames typically have metal hinges which are attached to the plastic components through simple fastening means such as rivets or by ultrasonic insertion. Usually, the entire temple and front frame are made from one plastic material and only the actual hinge is made from metal.
More recently, eyewear frames have been produced which combine plastic and metal components, or having multiple plastic components, to provide optimal durability, comfort and fashion appeal. Such frames provide for a greater variety of styles and designs allowing them to meet rapidly changing fashion requirements.
However, the connection of components, particularly in temples, has a serious drawback. Since plastic materials contract and expand in various environments, many plastic components have a tendency to change their position with respect to other components. For example, plastic contraction or shrinkage results in the plastic components pulling away from metal components leaving unsightly gaps or spaces. Plastic expansion results in the plastic components pushing against the fixed metal components causing buckling or warping. Moreover, if the expansion or contraction of the plastic components is severe, the plastic and metal components may actually separate causing the frame to disassemble.
While initially this would not seem to be a significant problem, one must consider the typical conditions in which eyewear, particularly sunglasses, are employed. For example, sunglasses left on the dash of an automobile can reach temperatures in excess of 150.degree. F. (66.degree. C.). Although not as severe, sunglasses are also exposed to direct sunlight for several hours at temperatures often between 80.degree. and 100.degree. F. (21.degree. and 38.degree. C.) in normal wearing conditions. Conversely, eyewear worn during winter sporting activities, such as skiing or ice skating, can be exposed to below freezing temperatures for extended periods of time. Thus, it is clear that the method of attaching plastic components to other plastic components or to metal components must be capable of withstanding expansion or contraction of the primary plastic component caused by wide temperature changes without disrupting the plastic to plastic or plastic to metal connection.
To overcome these previous shortfalls, the present invention provides a connecting system wherein the interface between the two components includes a slideable collar which is affixed to the plastic component having the greatest tendency for movement and which can slide along the second component, typically a metal, and slide with the movement of the plastic component during expansion or contraction. This invention can be easily and cost effectively manufactured and provides for a plastic/metal or plastic/plastic interface capable of withstanding various changes in the plastic components due to shifts in temperature while protecting the integrity of the metal to plastic connection and the overall appearance of the eyewear frame.